Typical medium voltage (MV) power converters or so-called drive systems are formed of silicon-based topologies. Such systems do not meet advanced requirements being demanded by various industries to improve overall system performance and cost. Specific system challenges include higher fundamental frequency operation than currently available, e.g., up to 1000 Hertz (Hz) for direct drive applications, high performance MV drives to handle power demand within a medium power range (e.g., up to 20 megawatts (MW)), overall converter system efficiencies better than 97%, and reduced volumetric power density and footprint to improve system power density and cost. Current systems are not capable of such operation.
Rather, traditional multi-megawatt and multi-level medium voltage power converter technology based on silicon devices operate within the range of 0-120 Hz of fundamental frequency, 600 Hz switching, and efficiencies up to 95%. Operation at higher fundamental frequencies is prohibited due to high switching loss causing stiff system de-rating, dramatic system efficiency and power density reductions.